Unexpected Mechanism of Experimental Cancer Drugs

Recent brain cancer research reveals that experimental cancer drugs zavondemstat and QC6352 operate primarily by blocking the enzyme DHODH rather than their intended target KDM4, challenging fundamental assumptions about their anticancer mechanisms. Led by Professor Lenka Munoz at the University of Sydney, published in Nature Chemical Biology on October 6, 2026, the study demonstrates that these compounds cut off the supply of DNA building blocks required for rapid cancer cell division. The unexpected findings indicate that earlier studies utilizing QC6352 to investigate KDM4 biology must be reinterpreted, and ongoing clinical trials for zavondemstat may be targeting the wrong biological mechanism. Researchers emphasize that establishing a drug is true mechanism early is critical to prevent wasted research effort, avoid inappropriate patient selection, and ensure limited funding supports genuinely promising treatments.